An investigation is underway to piece together events which led to the detonation of a suspected IED on a Metro car traveling between two stations on Monday afternoon. A second device found at Ploshchad Vosstaniya Metro Station, was defused, according to Russia’s National Anti-Terrorism Committee.

Russian President Vladimir Putin, several European politicians and other world leaders expressed their condolences to those affected by the incident.

Vladimir Putin expressed condolences to the family and friends of those killed or injured in the St Petersburg metro explosion

St. Petersburg’s healthcare committee confirmed at least 25 people, including one child, have been hospitalized in the wake of the blast. The city’s entire transit system has been shut down as bomb squads and emergency services attend the scene.

Meanwhile, #StPetersburg has been trending worldwide as Twitter users shared their support for the city’s residents and those affected by the explosion, with many also using the #Prayforstpetersburg hashtag.